• Title/Summary/Keyword: Adaptive Algorithms

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Multiplication Free Adaptive Digital Filter (승산을 요하지 않는 적응 디지탈 필터)

  • Park, Tae-Ho;Cha, Il-Hwan;Yun, Dae-Hui
    • The Journal of the Acoustical Society of Korea
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    • v.6 no.2
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    • pp.15-18
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    • 1987
  • Multiplication free adaptive digital filtering algorithms are discussed. The proposed. The proposed algorithm uses delta modulation digital filter and the relevant filter weights are updated using the SIGN algorithms to realize an adaptive digital filter without multiplication operations. It is shown that the resulting algorithm can be implemented using simple up/down counting operations. The convergence characteristics of the proposed adaptive digital filtering algorithm and .others are investigated for a system identification problem.

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Adaptive Queue Management in TCP/IP Networks (TCP/IP 네트워크에서 적응적 큐 관리 알고리즘)

  • Kim, Chang Hee
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.6 no.2
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    • pp.153-167
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    • 2010
  • Traffic conditions, in particular number of active TCP flows, change dramatically over time. The main goal of this paper is an adaptive queue management algorithm that can maintain network state of high-throughput and low-delay under changing traffic conditions In this paper, we devise Probability Adaptive RED(PARED) that combines the more effective elements of recent algorithms with a RED core. It automatically adjusts its adaptive marking function to account for changes in traffic load and to keep queue length within the desired target queue length. We simulate that PARED algorithm results in under changes in traffic load and mixed traffic load. The simulation test confirm this stability, and indicate that overall performances of PARED are substantially better than the RED and ARED algorithms.

A Fuzzy Variable Step Size LMS Algorithm for Adaptive Antennas in CDMA Systems

  • Su, Pham-Van;Tuan, Le-Minh;Kim, Jewoo;Giwan Yoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.518-522
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    • 2002
  • This paper proposes a new application of Fuzzy logic to Variable Step Size Least Mean Square (VS-LMS) adaptive beamforming algorithm in CDMA systems. The proposed algorithm adjusts the step size of the Least Mean Square (LMS) by using the application of Fuzzy logic in which the increase or decrease of step size depends on the fuzzy inference results of the Mean Square Error (MSE). Computer simulation results show that the proposed algorithm has a better capacity of tracking compared with the conventional LMS algorithms and other variable step size LMS algorithms.

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Comparison of Adaptive Operators in Genetic Algorithms (유전알고리즘에서 적응적 연산자들의 비교연구)

  • Yun, Young-Su;Seo, Seoun-Lock
    • Journal of Intelligence and Information Systems
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    • v.8 no.2
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    • pp.189-203
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    • 2002
  • In this paper we compare the performances of adaptive operators in genetic algorithm. For the adaptive operators, the crossover and mutation operators of genetic algorithm are considered. One fuzzy logic controller is developed in this paper and two heuristics is presented from conventional works for constructing the operators. The fuzzy logic controller and two conventional heuristics adaptively regulate the rates of the operators during genetic search process. All the algorithms are tested and analyzed in numerical examples. Finally, the best algorithm is recommended.

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Performance comparisons of adaptive beamforming algorithms for a large distorted phased array (대규모 위상배열용 적응 빔 형성 알고리듬의 성능비교)

  • 강봉순;박성균
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.7
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    • pp.46-52
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    • 1998
  • This paper presents an experimenal proof for criteria of selecting an optimum adaptive beamforming (ABF) algorithm for a large distorted phased array. A single point target embedded in clutter model is suggested to compare four well-known ABF algorithms. These algorithms are tested to low variance and high variance real data for self-calibrating a large distored phased array. It is shown that these algorithms require at least one dominant scatterer with large radar cross section (RCS) or multiple scatterers with moderate RCS in the field of view. Experimental results are provided to demonstrate the comparisons of the four algorithems in terms of gain loss and image correlaion coefficient, along with corresponding reconstructed cross-range images and range-azimuth images.

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Study on Machine Vision Algorithms for LCD Defects Detection (LCD 결함 검출을 위한 머신 비전 알고리즘 연구)

  • Jung, Min-Chul
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.3
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    • pp.59-63
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    • 2010
  • This paper proposes computer visual inspection algorithms for various LCD defects which are found in a manufacturing process. Modular vision processing steps are required in order to detect different types of LCD defects. Those key modules include RGB filtering for pixel defects, gray-scale morphological processing and Hough transform for line defects, and adaptive threshold for spot defects. The proposed algorithms can give users detailed information on the type of defects in the LCD panel, the size of defect, and its location. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

A Least Squares Approach to Escalator Algorithms for Adaptive Filtering

  • Kim, Nam-Yong
    • ETRI Journal
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    • v.28 no.2
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    • pp.155-161
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    • 2006
  • In this paper, we introduce an escalator (ESC) algorithm based on the least squares (LS) criterion. The proposed algorithm is relatively insensitive to the eigenvalue spread ratio (ESR) of an input signal and has a faster convergence speed than the conventional ESC algorithms. This algorithm exploits the fast adaptation ability of least squares methods and the orthogonalization property of the ESC structure. From the simulation results, the proposed algorithm shows superior convergence performance.

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Blind Channel Estimator based on the RLS algorithm (RLS 알고리즘에 기반을 둔 블라인드 채널 추정)

  • 서우정;하판봉;윤태성
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.655-658
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    • 1999
  • In this study, We derived Recursive Least Squares(RLS) algorithm with adaptive maximum -likelihood channel estimate for digital pulse amplitude modulated sequence in the presence of intersymbol interference and additive white Gaussian noise. RLS algorithms have better convergence characteristics than conventional algorithms, LMS Least Mean Squares) algorithms.

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An Adaptive Event Detection Algorithm Based on Statistics of Subblock Images (블록 영상의 통계적 특성을 이용한 적응적 상황 검출 알고리즘)

  • 하영욱;김희태
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.875-878
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    • 1998
  • In this paper, an adaptive event detection algorithm is proposed, for which we use the statistics of subblock image and adaptive threshold levels. The adaptive threshold level for a parameter binarization is taken by averaging the corresponding paramerter obtained from several input images. As simulation results, it is shown that the proposed algorithm is much more adaptive to the input images and effective in event detection rate than the conventional difference based algorithms.

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The Tool Path Determination for Machining the Plane Curve by an Adaptive Mesh Generation Technique - Comparision among the Adaptive Linear Interpolation, Parabolic Interpolation & Linear-Parabolic Interpolation Method - (적응요소분할법에 의한 평면곡선가공의 공구경로 결정 - 적응요소직선보간과 적응요소포물선보간 및 혼합보간법의 비교 -)

  • Hyun, Chang-Heon
    • Journal of Industrial Technology
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    • v.12
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    • pp.69-76
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    • 1992
  • An attempt has been made to determination the NC milling machine's tool-path through the adaptive parabolic interpolation method & the adaptive linear-parabolic interpolation method in consideration of the economical machining time. The algorithms for the above-mentioned interpolation methods have been designed and the numerical experiments for these methods have been conducted with the existing adaptive linear interpolation methods for comparision.

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